The present invention relates broadly to semi-synthetic derivatives of the antibiotic XK-62-2 and the production thereof. The antibiotic XK-62-2 and fermentation production thereof are described in U.S. patent application Ser. No. 364,058, filed May 25, 1973.
As is disclosed in the aforementioned U.S. application the antibiotic XK-62-2 is produced readily by culturing actinomycetes such as Micromonospora sagamiensis, Micromonospora ochinospora and Micromonospora purpurea by methods usually employed in the culturing of actinomycetes. More specifically, strains of the above-mentioned microorganisms are inoculated into a liquid medium containing a carbon source which the microorganism can utilize such as sugars, hydrocarbons, alcohols, organic acids, etc.; inorganic or organic nitrogen sources and inorganic salts and growth promoting factors and are cultured at 25.degree.-40.degree. C. for 2 to 12 days. Isolation and purification of XK-62-2 is carried out by a proper combination of adsorption and desorption from ion exchange resins and active carbon and column chromatography using cellulose, Sephadex, alumina and silica gel. In this manner, XK-62-2 can be obtained in the form of the sulfate or in the free form.
XK-62-2 is a basic substance and is obtained as a white powder. XK-62-2 has a molecular formula C.sub.20 H.sub.41 N.sub.5 O.sub.7, and a molecular weight of 463. The substance is well soluble in water and methanol, slightly soluble in ethanol and acetone and insoluble in chloroform, benzene, ethyl acetate and n-hexane.